I recently replaced the front (both inner and outer w/ races) and rear wheel bearings. For some reason I still hear the typical 'bad wheel bearing' noise while driving. I packed the front bearings using Swepco Moly 101 grease.

Both front and rear bearings installed without any issue, it is a very straight forward procedure. I can't tell from what direction the noise is coming from. I was thinking of jacking up the rear end and putting it in gear to get the bearings turning. Maybe this will, at least, help me isolate where the problem my be.

Any ideas? What else could cause a noise similar to wheel bearing groan?

Thanks.

 

cv axle can sound the same right?

 

Not sure if the CV's can sound similar to wheel bearings when they need to be replaced. As far as I know a worn CV will start out clicking and get worse from there.

Does anybody know if by jacking up the rear end, getting in gear and bringing the wheel speed up produce the bearing noise? Not sure if the weight of the car loading the suspension plays a factor.

 

I had a similar issue recently. I put my spare front spindles and hubs on and it made no difference. It turned out to be a passenger rear that was bad. I just changed both rears. It's hard to figure out sometimes where the noise is coming from. I could have sworn it was drivers front.

Rears are hard to test. I had to put the car and jack stands and run it to find which one was bad. I used a stethescope, on the bearing housing to hear it.

 

good idea with the stethoscope. Ill give it a shot.

I just replaced both rears with new bearings. What are the odd that one of the NEW bearings is no good??

 

Did you find a bad bearing when you took the old ones out?
A bad rear bearing will show a lot of play once the caliper has been removed (the caliper actually keeps the wobble in check).

What is your definition of a bad bearing sound? (fronts and rears are quite different)

 

Actually the front bearings looked to be in good shape. I used this method to remove the rear......http://www.arnnworx.com/RearBearings.htm

The slide hammer ruins the old bearing so I don't know how good or bad shape they were in.

Though to describe sounds but here goes...
It sounds like a hollow WHUUUOOOOOOO that changes slightly according to your speed. I notice it more at slower speeds, probably due to less road noise.

WHOOOOOOOOOOOOOoooooooooooooooooo..... lowering in volume as I come to a stop.

 

Usually rear wheel bearings 'groan' and the sound changes pitch with speed.
Sometimes a tire with a bad belt can make some interesting noises!

 

I does sound like a hollow groan. Ill jack up the rear and try to reproduce it. Thats easy enough to do.

 

What kind of tires do you have? I thought for sure I had a bad bearing, but turned out to be only tires. RE730's are the worst!!!

 

I think those are the tires I have!! Ill have to check when I get home.

 

If you have RE730's then I am willing to bet it is the tires. Check out all of the complaints on Tirerack.com. I could not believe the difference when I removed them and installed a different set from another car, Fuzions I think. Noise totally dissappeared! See my other post, I am getting ready to buy a new set of tires this week.

 

Those are the EXACT tires I have. Potenza RE730's in the back and RE040's in the front. All of them need to be replaced.

I jacked up the rear and brought it up to 60MPH and heard no bearing noise at all.

 

Bingo!!!

Evidentally, those tires SUCK!

I have two '89's, one in FL and one in CA. I just bought the one in CA a couple months ago. The previous owner had just bought these tires in January. They have 2,000 miles on them, but they have to go. He took $500 off the price of the car because I told him the bearings were going and he agreed. I am going to use that towards the new tires. Maybe somebody who has a very loud stereo will buy these on Craigslist. A week later I found the complaints on Tirerack about the 730's and took my car over to the local Porsche shop. Fortunately, there was another '89 there and we swapped the wheels, noise gone immediately. Now I am pondering which tires to buy. There is another active topic on that right now. You might want to read that as well.

 

tires are not in the budget at the moment but I will keep an eye on that thread for when the time comes.

THANKS!!